Linux 服务器磁盘在线扩容

CentOS 7 非 LVM 根分区扩容步骤

1、查看现有分区大小

[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 3.8G 0 3.8G 0% /dev
tmpfs tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs tmpfs 3.9G 13M 3.8G 1% /run
tmpfs tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda3 xfs 18G 18G 654M 97% /
/dev/sda1 xfs 297M 164M 134M 55% /boot
tmpfs tmpfs 781M 48K 781M 1% /run/user/1000
tmpfs tmpfs 781M 0 781M 0% /run/user/0
[root@localhost ~]#

如果你的磁盘空间还很大，可以快速写入一个大文件将磁盘空间填充
下面的命令是快速的生成一个文件名为 big_file 大小为 1300*10MB 大小的文件
[root@localhost ~]# dd if=/dev/zero of=big_file count=1300 bs=10MB

2、对磁盘空间进行扩容，扩容后再查看磁盘空间的大小

[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 3.8G 0 3.8G 0% /dev
tmpfs tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs tmpfs 3.9G 13M 3.8G 1% /run
tmpfs tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda3 xfs 18G 18G 655M 97% /
/dev/sda1 xfs 297M 164M 134M 55% /boot
tmpfs tmpfs 781M 8.0K 781M 1% /run/user/42
tmpfs tmpfs 781M 0 781M 0% /run/user/0
[root@localhost ~]#

[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 25G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 17.7G 0 part /
sr0 11:0 1 1024M 0 rom
[root@localhost ~]#

3、进行分区扩展磁盘

[root@localhost ~]# fdisk /dev/sda
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Command (m for help): p

Disk /dev/sda: 26.8 GB, 26843545600 bytes, 52428800 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000ad816

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 616447 307200 83 Linux
/dev/sda2 616448 4810751 2097152 82 Linux swap / Solaris
/dev/sda3 4810752 41943039 18566144 83 Linux

Command (m for help): d
Partition number (1-3, default 3):
Partition 3 is deleted

Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p
Partition number (3,4, default 3):
First sector (4810752-52428799, default 4810752):
Using default value 4810752
Last sector, +sectors or +size{K,M,G} (4810752-52428799, default 52428799):
Using default value 52428799
Partition 3 of type Linux and of size 22.7 GiB is set

Command (m for help): p

Disk /dev/sda: 26.8 GB, 26843545600 bytes, 52428800 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000ad816

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 616447 307200 83 Linux
/dev/sda2 616448 4810751 2097152 82 Linux swap / Solaris
/dev/sda3 4810752 52428799 23809024 83 Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@localhost ~]#

4、刷新分区

[root@localhost ~]# partprobe /dev/sda

5、查看分区状态

[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 25G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 22.7G 0 part /
sr0 11:0 1 1024M 0 rom
[root@localhost ~]#

6、刷新根分区并查看状态

[root@localhost ~]# xfs_growfs /dev/sda3
meta-data=/dev/sda3 isize=512 agcount=4, agsize=1160384 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=4641536, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 4641536 to 5952256
[root@localhost ~]#

[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 3.8G 0 3.8G 0% /dev
tmpfs tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs tmpfs 3.9G 13M 3.8G 1% /run
tmpfs tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda3 xfs 23G 18G 5.7G 76% /
/dev/sda1 xfs 297M 164M 134M 55% /boot
tmpfs tmpfs 781M 12K 781M 1% /run/user/42
tmpfs tmpfs 781M 0 781M 0% /run/user/0
[root@localhost ~]#